1. Field of the Invention
The present invention relates to an organic light emitting device and method for fabricating the same, and more particularly, to an organic light emitting device, and method for fabricating the same, in which a data line and a power line of a unit pixel region may be formed in a trench and be overlapped by a pixel electrode.
2. Discussion of the Background
Flat panel display devices, including a liquid crystal display (LCD) device, an organic light emitting display device, and a plasma display panel (PDP), have recently received a lot of attention as replacements for large and heavy conventional cathode ray tubes (CRT).
The LCD device is not self-emitting. Therefore, its brightness, contrast, viewing angle and size may be limited. While the PDP is self-emitting, it is generally heavier than other flat panel display devices, it requires high power consumption, and it may be complicated to fabricate. The organic light emitting display device is self-emitting, so that it is advantageous in terms of viewing angle, contrast, etc. Since it does not require a backlight, power consumption may be reduced, and it may be fabricated as a small-sized and light-weight display device.
Additionally, the organic light emitting display device may be driven by a direct current and low voltage, and it has a fast response speed. Furthermore, the organic light emitting display device is made of a solid material, so that it has a wide temperature range, it is not easily damaged by external impact, and it may be fabricated cheaply and easily.
FIG. 1A and FIG. 1B are a plan view and a cross-sectional view showing a conventional organic light emitting device, respectively.
As FIG. 1A shows, a switching thin film transistor (TFT) 15, a driving TFT 16, a capacitor 17, and a first electrode 18 may be formed within a unit pixel region defined by a scan line 12, a data line 13, and a power line 14, which may be formed on a transparent substrate 11 such as plastic or glass. The capacitor 17 supplies a current while the organic light emitting device emits light, and the first electrode 18, which is a pixel electrode, may be electrically connected to either a source or drain electrode of the driving TFT. Although not shown in FIG. 1A, an organic layer including at least an organic emission layer and a common, second electrode may be formed on the first electrode.
FIG. 1B is a cross-sectional view taken along line A–A′ of FIG. 1A. As FIG. 1B shows, insulating layers, such as a buffer layer 21, a gate insulating layer 22, and an interlayer insulating layer 23, may be formed on a substrate 11, and a data line 13 and a power line 14 may be formed on the interlayer insulating layer 23. A passivation layer 24 and a planarization layer 25 may be subsequently formed on the data line 13 and the power line 14, and the first electrode 18 may be formed on the planarization layer 25.
In this case, the first electrode 18 may be separated from the data line 13 and the power line 14 by a predetermined interval 31 such that electrical signals do not affect the first electrode 18, thereby preventing crosstalk when supplying electrical signals to the data line 13 and the power line 14. In the conventional organic light emitting device, however, the first electrode 18 may be separated from metal interconnections, such as the data line and the power line, by a predetermined interval, which may decrease the display device's aperture ratio.